The major projects in this application involve a continuation of studies to determine primary structures of airborne allergens, identify major allergenic and antigenic sites of these allergens, and eventually utilize this information to produce products with potential for desensitization therapy. Specifically, purified allergens are being isolated in this laboratory from defatted short ragweed pollen (Ambrosia elatior) and from a series of grass pollens. All of these pollens contain allergens which we have been able to purify by molecular sieve, ion exchange, and high pressure liquid chromatography. Those allergens purified in the laboratory include, antigen E, Ra3, Ra5, and Ra6 from short ragweed and the major rye I proteins from grasses. In addition to those allergens, we have received (for structural studies only) Ra5 from giant ragweed and a cytochrome with documented human allergic reactivity from Kentucky blue grass. The ability to determine complete amino acid sequences by automated Edman degradation allows us to pursue studies relating to important questions such as which parts of these molecules act as immunologic determinants in a much more rational way than would otherwise be possible. A number of hybridoma antibodies have been raised to antigen E, Ra6, and rye grass I in the past year or so. More such antibodies will be raised against these and other allergens under study in the laboratory. These hybridoma antibodies are raised after immunization of BALB/c mice, removal of spleens, and fusion to one of 3 murine neoplastic cell lines. Alkaline phosphatase ELISA assays have been developed to allow screening for antibody producing clones, and a series of binding and inhibition assays has been developed to detect antigenic fragments of allergens and determine which antigenic sites are recognized by human allergic sera.